Meter socket base assembly

ABSTRACT

A flanged cup is inserted in an aperture in an insulation plate from one side, and a terminal strap and a plug-in contact jaw member are secured by a screw and nut to a flat bottom of the cup on the other side of the insulation plate.

I Umted States Patent 1151 3,662,323

Stanback 1 May 9, 197 2 [54] METER SOCKET BASE ASSEMBLY References Cited [72] Inventor: Harris I. Stanback, Lexington, Ky. UNITED STATES PATENTS 73 Assigneei square D Company, Park Ridge L 2,697,185 12/1954 Johansson 339/198 5 2,865,013 12/1958 Kazanowsk1.. .....339/272 [22] Filed: May 18, 1970 2,352,045 6/1944 Von Opel ..24/221 3,187,296 6/1965 Braekett 339/217 8 1 38,472 2,880,380 3/1959 Schmidt et a1. ..317/109 Related U.S.APPlica'ion Data 2,647,243 7/1953 Clark ..339/31 B [63] Continuation of Ser. No. 771,463, Oct. 29, 1968, m' Examiner-Marvin Champion abandoned Assistant E.\'aminerRobert A. Hafer AtmrneyHarold J. Rathbun and Paul .1. Rose [52] U.S. Cl. ..339/198 M, 339/31 B, 339/217 R 511 1111. c1 ..H0lr 9/00 [57] ABSTRACT [58] Field 01 Search ..339/217, 214, 215, 31, 198 M; A flanged cup is inserted in an aperture in an insulation plate 317/l05-1 1 1 from one side, and a terminal strap and a plug-in contact jaw member are secured by a screw and nut to a flat bottom of the cup on the other side of the insulation plate.

4 Claims, 4 Drawing Figures PATENTEUMAY 9 m2 3.662.323

INVENTOR.

HARRIS Z SUM/BACK EH-g METER SOCKET BASE ASSEMBLY This application is a continuation of application, Ser. No. 771,463, filed Oct. 29, 1968, now abandoned.

This invention relates to an improved meter socket base assembly for watt-hour meters. Formerly the contact jaw members and terminal straps of meter sockets were mounted on insulation members of block form. Consequently, a relatively large amount of insulating material was required. To reduce the amount of insulating material required, a sheet of insulating material was used as a base and the contact jaw members and terminal straps were clamped thereto. Shrinkage of the sheet of insulating material in use reduced the contact pressure between the contact jaw members and their respective terminal straps, resulting in poor electrical connections.

In accordance with this invention, the contact jaw members and terminal straps are mounted on a sheet or plate of insulating material, hereinafter called an insulation plate, in such a manner that in effect the insulation plate is not a part of the clamped joint at any contact jaw member and its respective terminal strap. Thus, any shrinkage of the insulation plate in use does not cause deterioration of the electrical connection between any contact jaw member and its respective terminal strap.

Accordingly, an object of the invention is to provide an improved meter socket base assembly for watt-hour meters.

A further object is to provide a means of mounting a contact jaw member and a terminal strap on an insulation plate whereby shrinkage of the insulation plate does not cause deterioration of the electrical connection between the contact jaw member and terminal strap.

In the drawings,

FIG. 1 is a front view of a meter socket base assembly constructed in accordance with the invention;

FIG. 2 is a side elevational view of the meter socket base assembly of FIG. 1;

FIG. 3 is a fragmentary sectional view taken along the line 33 of FIG. 1; and

FIG. 4 is an exploded perspective view of the portion of the base assembly shown in FIG. 3.

A meter socket base assembly constructed in accordance with the invention includes a body of insulating material in the form of a relatively thin, flat, generally rectangular sheet or plate. The insulation plate 10 may be fiberglass reinforced polyester resin. In the embodiment shown, four plug-in contact jaw members 12 are secured to the insulation plate 10 in proper position respectively to receive four contact blades of a watt-hour meter (not shown). As best shown in FIG. 2, the two upper contact jaw members 12 are provided respectively with a pair of relatively long terminal straps 14 and the two lower contact jaw members 12 are provided respectively with a pair of relatively short terminal straps 16. The length of the terminal straps l4 and 16 is dependent upon the position of respective bus bars (not shown) to which they are attached when in use. As shown, the terminal straps l4 and 16 are generally Z-shaped, and each includes a front end portion disposed on the front side of the insulation plate 10 and a rear end portion spaced from the front end portion in a direction perpendicular to the insulation plate 10 and disposed on the rear side of the plate.

The manner of securing the contact jaw members 12 and the terminal straps 14 and 16 to the insulation plate 10 is best shown in FIGS. 3 and 4. Respectively adjacent four comers thereof, the insulation plate 10 is provided with four holes 17, one of which is shown in FIG. 4. Four cup members 18 each having a curved flange 18a and a flat bottom 1812 are received respectively in the holes 17 from the rear side of the insulation plate 10, only one of the cup members 18 being shown. The curved flange 18a of each cup member 18 is concave toward the bottom 18b. The bottom portion 18b of each cup member 18 is provided with an appropriate hole large enough to receive the threaded shank portion of a screw 20 but small enough to prevent passage of the enlarged head portion of the screw. Each of the contact jaw members 12 and the front end portions ofthe terminal straps 14 and 16 is also provided with an appropriate hole for reception of the threaded shank portion of a screw 20. Each screw 20 is threaded into a nut 22 disposed within the respective contact jaw member 12 and held against rotation thereby. The contact jaw members 12 are respectively held against rotation by raised boss or dimple portions 140 and 16a disposed respectively on the front end portions of the terminal straps 14 and 16.

The contact jaw members 12, nuts 22, and the front end portions of the terminal straps 14 and 16 are disposed on the opposite side of the insulation plate 10 from the curved flanges 18a of the cup members 18, each of the front end portions of the terminal straps 14 and 16 being disposed between the bottom 18b of the respective cup member 18 and the respective contact jaw member 12. The thickness of the insulation plate 10 is substantially equal to the distance from the edge of the flange 18a of a cup member 18 to the outer surface of the bottom 18b of the cup, and substantially no clamping pressure is applied to the insulation plate 10. Any shrinkage of the insulation plate 10 in use has no effect on the electrical connection between each contact jaw member 12 and its respective terminal strap 14 or 16.

Various modifications may be made in the structure shown and described without departing from the spirit and scope of the invention.

1 Claim:

1. A meter socket base assembly comprising a flat generally rectangular plate of insulating material having four apertures extending therethrough respectively adjacent four corners thereof, four flat-bottomed flanged cups disposed respectively in said apertures, each cup having a flange portion disposed on a rear side of the plate in overlapping relationship with a portion thereof defining the respective aperture and having an outer surface of a flat bottom portion substantially flush with a front surface of the plate, four terminal straps each having a front end portion disposed on a front side of the plate generally in alignment with a respective one of the apertures and a rear end portion spaced from the front end portion and from the plate in a direction perpendicular to the plate and disposed on the rear side of the plate, four plug-in contact jaw members disposed on the front side of the plate generally in alignment respectively with the apertures, and fastening means securing the front end portions of the terminal straps and the contact jaw members respectively in electrical contact with each other and clamping them respectively against the bottom portions of the cups.

2. A meter socket base assembly as claimed in claim 1 wherein each of the contact jaw members is disposed on the opposite side of the respective front end portion of the terminal strap from the insulation plate.

3. A meter socket base assembly as claimed in claim 2 wherein the fastening means includes a plurality of nuts and screws, the nuts being disposed respectively within the contact jaw members and the screws having head portions disposed respectively within the flanged cups.

4. A meter socket base assembly comprising a flat generally rectangular plate of insulating material, four terminal straps each having a front end portion disposed on a front side of the plate and secured to a corner portion thereof and a rear end portion spaced from the front end portion and from the plate in a direction perpendicular to the plate and disposed on the rear side of the plate, and four plug-in contact jaw members electrically connected and mechanically secured respectively to the front end portions of the terminal straps, the rear end portions of the terminal straps being securable respectively to bus bars, whereby the terminal straps form a support for the plate and contact jaws. 

1. A meter socket base assembly comprising a flat generally rectangular plate of insulating material having four apertures extending therethrough respectively adjacent four corners thereof, four flat-bottomed flanged cups disposed respectively in said apertures, each cup having a flange portion disposed on a rear side of the plate in overlapping relationship with a portion thereof defining the respective aperture and having an outer surface of a flat bottom portion substantially flush with a front surface of the plate, four terminal straps each having a front end portion disposed on a front side of the plate generally in alignment with a respective one of the apertures and a rear end portion spaced from the front end portion and from the plate in a direction perpendicular to the plate and disposed on the rear side of the plate, four plug-in contact jaw members disposed on the front side of the plate generally in alignment respectively with the apertures, and fastening means securing the front end portions of the terminal straps and the contact jaw members respectively in electrical contact with each other and clamping them respectively against the bottom portions of the cups.
 2. A meter socket base assembly as claimed in claim 1 wherein each of the contact jaw members is disposed on the opposite side of the respective front end portion of the terminal strap from the insulation plate.
 3. A meter socket base assembly as claimed in claim 2 wherein the fastening means includes a plurality of nuts and sCrews, the nuts being disposed respectively within the contact jaw members and the screws having head portions disposed respectively within the flanged cups.
 4. A meter socket base assembly comprising a flat generally rectangular plate of insulating material, four terminal straps each having a front end portion disposed on a front side of the plate and secured to a corner portion thereof and a rear end portion spaced from the front end portion and from the plate in a direction perpendicular to the plate and disposed on the rear side of the plate, and four plug-in contact jaw members electrically connected and mechanically secured respectively to the front end portions of the terminal straps, the rear end portions of the terminal straps being securable respectively to bus bars, whereby the terminal straps form a support for the plate and contact jaws. 